High voltage switching circuits using semiconductor technology are known for switching high voltages. In order to be able to switch high voltages with relatively easy damageable semiconductors, these switching circuits are split in several stages each of which undergoes only part of the overall voltage.
Several types of switching circuits (crowbars) are known. However, most of them use plural toroid cores or complex auxiliary supplies for driving the semiconductors. Others implement a sort of master slave configuration or cascade arrangement, in which only one stage (the master) is driven and the others follow consecutively.
EP 2 040 379 A2 describes a circuit for servicing a load connectable with a power supply. The circuit comprises a plurality of three-terminal switches and one control supply. The three-terminal switches define a series conduction path connectable between the power supply and the load. The three-terminal switches include a source terminal, a drain terminal and a gate terminal. The circuit further includes an isolation circuit disposed between a control supply and the gate terminal of each switch. The isolation circuit operates in conjunction with the control supply and the controller to provide an isolated voltage at the gate terminals of each switch such that an open switch potential does not exceed the control voltage required to close the connection.
However, this design is rather complex such that there is a need for a switching circuit with a more simplified design.